38 INSECTS AT HOME. 



something like that of the Carabus, flattened and scaly on the 

 upper surface of each segment and the liead. It has two large, 

 sharp, curved, and powerful mandibles, from which no cater- 

 pillar has a chance of escape, and there are two horny spines at 

 the end of the tail. Its length, when full-grown, is about an 

 inch and a half. 



The voracity of this larva is amazing. It will eat several 

 caterpillars, and even pupae, daily, and gorges itself to such an 

 extent that the soft body becomes quite distended like that of 

 a full-fed leech, and the creature is quite incapable of moving. 

 In this condition it often falls a victim to its own voracity, and 

 that in rather a curious manner. It has been mentioned that, 

 among other insects, the Processionary Moth forms a large 

 proportion of its food. Now the caterpillars of this moth are 

 social in their habits, and spin large webs, in which they live 

 together. Into these nests the larva of the Calosoma is sure to 

 creep, and sometimes as many as five or six have been found in 

 the same web, feeding on the inmates. Sometimes it happens that 

 a Calosoma grub, hungry and wandering in search of food, dis- 

 covers a nest of Processionary caterpillars, and straightway makes 

 its entrance. Being very hungry, it seizes the first creature 

 to which it comes, and sometimes catches its gorged and help- 

 less relative, which it devours without the least compunction. 



I have already mentioned that the Calosoma is in all proba- 

 bility the means of preserving the supply of fir-wood. In some 

 years, as often happens with destructive insects, sundry pine- 

 feeding caterpillars absolutely swarm in the forest, the insect 

 armies being so vast that anyone walking through the forest 

 hears the sound of their busy jaws on every side as they devour 

 the leaves. With any tree such a visitation would be a mis- 

 fortune, but with the pine-trees it is death. Ordinary trees, 

 if stripped of their leaves, will put forth a fresh set of foliage 

 in the succeeding year, and suffer little except being thrown 

 back in their growth ; but a pine-tree, when deprived of its 

 leaves, has no such power, and always dies. The reader will, 

 therefore, see how invaluable are the services rendered to man 

 by this insect, which keeps down the numbers of the obnoxious 

 caterpillars, and saves whole forests from destruction. 



Trees that have been perishing through the attacks of cater- 

 pillars have been saved by the Calosoma. Some years ago, 



